Electrical contact element for electrical connector having surface texture

Abstract

A conductive contact element for an electrical connector is provided having a connection region and a contact region. The contact region 8 comprises a main region 2, an edge region 4, and a contact surface 5. The contact surface 5 is arranged on at least one face 50, 51 (not shown in the selected drawing), 52, 53 of the main region 2 and on at least one face 50, 51 (not shown in the selected drawing), 52, 53 of the edge region 4. Only inside the contact surface 5 of the edge region 4, cavities filled with an auxiliary material are arranged in a microstructure, and in the region of the microstructure, the contact surface 5 has a surface texture.

Description

[Technical Field]

[0001] The present invention relates to a conductive contact element for an electrical connector having a contact surface, and to an electrical connector including such a contact element.

[0002] Also described herein is a method for encapsulating a supplemental material within the contact surface of an end region of a contact area of ​​a conductive contact element for an electrical connector. [Background technology]

[0003] Numerous designs of electrical connectors and their contact elements are known in the prior art. Electrical connectors are intended to mate with a suitable mating connector to establish an electrical connection. An electrical connector can generally be defined as an electromechanical system used for either signal or power transmission, providing a separable interface between two electronic subsystems. For this purpose, electrical connectors generally have conductive contact elements that come into contact with contact elements of a mating connector when the connectors are mated. The contact elements of one connector are often designed as contact pins, while the contact elements of the mating connector are often designed as spring contacts. When the connector and the mating connector are mated together, the spring contacts exert a resilient spring force on the contact pins, ensuring a reliable conductive connection.

[0004] Electrical connectors are used in automobiles, for example, to transmit power and network electrical-electronic systems. In automobiles, connectors are exposed to severe temperature fluctuations, vibrations, and corrosive media. Increased operating temperatures lead to increased wear, especially in the case of the widely used tin-plated copper-based contact elements. The most serious wear mechanism is fretting corrosion. This vibration wear, caused by micro-vibrations, leads to the formation of an insulating oxide layer in the contact area and thus to connector malfunction.

[0005] Base contact surfaces, for example, made of tin, nickel, or their alloys, are particularly susceptible to friction corrosion (fretting or galling) when small relative movements occur. Furthermore, the mating forces of multi-position connectors are often outside the range of values ​​required by consumers. When using expensive contact surfaces, for example, based on precious metals, the tendency to cold weld is a known issue.

[0006] In addition to high wear resistance, low mating and withdrawal forces are required to facilitate assembly and maintenance of the connector.

[0007] In addition, during mating of the connector with the mating connector, the contact surfaces of the contact elements are partially worn away, and this wear caused by abrasion limits the mating frequency of the connectors, thereby reducing their operating time.

[0008] To optimize the mating force, a microstructure is formed on the inside of the contact surface of the contact element in a conventional connector, and an auxiliary material is encapsulated in this microstructure. When the connector is mated with a mating connector, the contact surface is slightly torn open to reveal the auxiliary material. In the conventional connector, the entire contact surface of the contact element is structured. Not only does leakage of the auxiliary material reduce the mating force, but the auxiliary material adhering to the contact surface can also reduce electrical conductivity and therefore result in a less stable electrical contact. In addition, when manufacturing contact elements, especially when forming the microstructure using a laser, it is only possible to structure the surface facing the laser. Depending on the connector type, this may not be the optimal surface for reducing the mating force.

[0009] Since the laser structuring process is an automated process, multiple contact elements are arranged on the carrier rail at intervals of a few millimeters and structured one by one using a laser. Due to this arrangement on the carrier rail, the surfaces facing the adjacent contact elements cannot be irradiated because the laser beam cannot reach them.

[0010] This means that only the side facing the laser can be irradiated and thereby structured, which may result in an insufficient reduction in mating force. Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, there is a need for improved connector contact elements that minimize mating forces while maintaining consistent long-term electrical performance. [Means for solving the problem]

[0012] This problem is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0013] The invention includes the idea that it is not necessary to structure the entire contact surface of the contact element to achieve a lower mating force. The highest mating force needs to be overcome at the front of the contact element, but the contribution of the mating force decreases along the length of the contact element. This means that it is sufficient to structure only a portion of the contact element.

[0014] In particular, the invention provides an electrical contact element having a connection region and a contact region. The contact region comprises a main region, an end region, and a contact surface for electrical contact with a mating contact element of a mating connector. The contact surface is arranged on at least one side of the main region and on at least one side of the end region, and only inside the contact surface of the end region, cavities filled with an auxiliary material are arranged in a microstructure. In addition, the contact surface partially has a surface texture in the region of the microstructure.

[0015] The solution according to the present invention firmly embeds the auxiliary material in the contact element by filling the cavities located in the surface texture inside the contact face. This prevents the auxiliary material from being adversely affected, such as resinification. The firmly embedding of the auxiliary material prevents undesired loss of the auxiliary material. In addition to liquid auxiliary material, solid auxiliary material may also be encapsulated in the surface texture of the cavities in this way. Additionally, locating the microstructure in the area where the mating force is greatest but where no electrical contact with the mating connector is made ensures that leaked auxiliary material does not affect electrical performance.

[0016] Auxiliary materials, also called additives, are substances added in small amounts to achieve or improve a particular property.

[0017] A cavity is an artificially formed cavity inside the contact surface. The arrangement of the cavity below the contact surface means that the cavity has no outlet at the contact surface, or at most an outlet so narrow that it is not possible to reach the auxiliary material filled in the cavity without forming a breakthrough from the contact surface to the cavity.

[0018] According to an advantageous further development of the invention, the surface texture comprises ridges and depressions, the arrangement of which results in a surface texture with a predetermined pattern of geometric elements.

[0019] A textured surface and / or surface texture is a surface with a definite pattern of geometric elements. These elements may have a high ratio of the structure's depth or height to its lateral extent. The textured surface may be periodic in at least one direction. Examples of textures are ridges or recesses in contact surfaces with circular, elliptical, square, linear, or V-shaped cross sections. The surface texture or textured surface reduces the contact area between the contact surfaces of the contact element and the mating connector when the connector and mating connector are mated. This reduces the frictional forces acting between the contact surfaces, advantageously reducing the required mating force. Additionally, the textured surface reduces the electrical contact resistance between the contact surfaces of the connector and the mating connector by increasing the contact points between the contact surfaces. An additional benefit is that wear on the contact surfaces is reduced by texturing.

[0020] According to a further advantageous development of the invention, the microstructure forms at least a partially periodic structure, which has the advantage of being easy to manufacture and reproducible, and which can form, for example, a line pattern, a dot pattern, a honeycomb pattern, a cross pattern, etc.

[0021] A microstructure is a fine structure in the micrometer range. It is a substantially regular arrangement of specific elements, in this case cavities. The spatial dimensions of the cavities are preferably in the range of 0.1 to 50 μm.

[0022] The microstructures may, for example, extend parallel to the contact surface and be arranged close to the surface, thereby ensuring that during wear openings are formed from the contact surface into the cavities of the microstructures, allowing the auxiliary material to leak from the cavities onto the contact surface, where it achieves the desired positive effect.

[0023] According to a further advantageous development of the invention, the geometric elements of the surface texture are raised above the respective cavities of the microstructure. In this embodiment, the contact surface can be textured with knobs, in which cavities filled with an auxiliary material are arranged. This allows the advantages of a textured contact surface and a cavity microstructure with an auxiliary material located inside the contact surface to be realized in a particularly simple and space-saving manner. Of course, it is also possible to arrange the surface texture and the cavity microstructure alternately, i.e., offset from each other.

[0024] According to a further advantageous development of the invention, at least two side surfaces of the end region of the contact area are tapered in the insertion direction of the contact element along the longitudinal axis L. Advantageously, the at least two tapered sides of the end region each have two converging edge contours that converge in such a way that each edge contour at least partially follows the path of a cubic function graph, the path of the cubic function graph depending on the path of the longitudinal axis L.

[0025] According to a further advantageous development of the invention, the cubic function graph is

number

[0026] When mating a connector with a mating connector, the majority of the mating force must be applied to the end region of the contact area of ​​the contact element, which must spread the spring contacts of the mating contact element. As a result, optimizing the shape and reducing the mating force in this region is particularly important. An advantageous design of the end region further reduces the mating force, and the contact element is also insensitive to the geometry of the mating contact element.

[0027] According to a further advantageous development of the invention, the auxiliary material may be selected from the group consisting of antioxidants, corrosion inhibitors, lubricants and acids. The auxiliary material may be a solid or liquid auxiliary material, for example, an oil, grease, paste or solid lubricant such as graphite, carbon nanotubes (CNTs), MoS2, AgS2 or a mixture of these substances.

[0028] The contact element according to the present invention can be manufactured by the following method.

[0029] A method for encapsulating an auxiliary material inside a contact surface of an end region of a contact element for an electrical connector, the method comprising the steps of applying an auxiliary material to the contact surface of the end region, forming a microstructure on the contact surface of the end region, and encapsulating the auxiliary material in cavities of the microstructure inside the contact surface of the end region. A surface texture in the form of a predetermined pattern of geometric elements is formed on the contact surface of the end region, and the contact surface of the end region is treated with laser radiation to form the microstructure. The laser radiation impinges transversely on the contact surface of the end region, rather than perpendicularly to the longitudinal axis L of the contact element.

[0030] In one embodiment of the method described above, the laser radiation strikes the contact surface of the end region at an angle β relative to the longitudinal axis L of the contact element, this angle β ranging between 0°<β<90°.

[0031] By forming surface textures and microstructures in the end regions of the contact elements, any side of the contact element can be advantageously treated with laser radiation, including the side of the contact element that faces the adjacent contact element when placed on the carrier rail.

[0032] The further advantageous shape of the end region also means that uniform irradiation is possible, since the laser beam does not strike the contact element perpendicularly to the longitudinal axis L, but rather strikes the surface of the end region to be irradiated in a direction transverse to it. Advantageously, with this type of irradiation, microstructures can be formed over large areas in a very short time, accurately and reproducibly.

[0033] In a particularly advantageous embodiment, the contact surface is treated with an interference pattern of laser radiation to form a microstructure. Two or more superimposed, preferably coherent, linearly polarized laser beams generate a selectively adjustable interference pattern. The intensity of the laser radiation is distributed within the interference pattern. In the case of positive interference, this increases, resulting in particularly hot areas where the contact surface melts. On the other hand, at minimum intensity, the contact surface is significantly cooler, so the contact surface does not melt, i.e., all auxiliary material present there remains, while in the areas of positive interference it evaporates. In addition, the large temperature gradient between the lowest temperature (in the areas of negative interference) and the highest temperature (in the areas of positive interference) leads to convection of the molten material at the contact surface and the formation of a texture. The texture is formed when material at the contact surface is transported from the hottest area to the coldest area.

[0034] In a further embodiment of the above-described method, the auxiliary material may be applied to the contact surface first, and then the microstructure may be formed. For example, the contact surface may first be coated with the auxiliary material, i.e., completely covered, which facilitates the application of the auxiliary material. After forming the microstructure, the auxiliary material is applied to the areas where the cavities will later be formed, i.e., the areas where the auxiliary material will be enclosed in the microstructure. For this purpose, the contact surface is treated with laser radiation.

[0035] According to one embodiment, the auxiliary material may be encapsulated in the microstructure during its formation, whereby the steps of forming the microstructure and encapsulating the auxiliary material in the microstructure, i.e. in the cavities of the microstructure, are performed in one step, thereby speeding up the method described above.

[0036] For a better understanding of the present invention, the present invention will be described in more detail with reference to the embodiments shown in the following drawings. The same parts are designated by the same reference numerals and the same component names. Furthermore, some features or combinations of features in the various embodiments shown and described may correspond to independent inventive solutions or solutions according to the present invention. [Brief explanation of the drawings]

[0037] [Figure 1] 3A and 3B are schematic cross-sectional views of mating of a contact element with a mating contact element; [Figure 2] 1 is a schematic side view of a contact element according to the present invention; [Figure 3a] 1 is a schematic top view of a contact element according to the present invention; [Figure 3b] 1 is a schematic top view of a contact element according to the present invention having an R; [Figure 4a] 2 is a schematic diagram of a top view of a contact element according to the present invention; [Figure 4b] 2 is a schematic view of a surface of a contact element according to the present invention; [Figure 5] 2 is an enlarged schematic view of a surface of a contact element according to the present invention; [Figure 6a] 10 is a schematic diagram of a further embodiment of the top surface of a contact element according to the present invention; [Figure 6b] 10A-10C are schematic diagrams of further embodiments of the faces of contact elements according to the present invention; [Figure 7a] 10 is a schematic diagram of a further embodiment of the top surface of a contact element according to the present invention; [Figure 7b] 10 is a schematic diagram of a further embodiment of the top surface of a contact element according to the present invention; [Figure 7c] 10A-10C are schematic diagrams of further embodiments of the faces of contact elements according to the present invention; [Figure 8] 10A-10C are schematic diagrams of further embodiments of the faces of contact elements according to the present invention; [Figure 9] 1 is a schematic diagram of a surface treatment of a contact surface using a laser according to the method of the present invention; [Figure 10] 3 is a schematic cross-sectional view of the contact surface after laser processing by the above method. FIG. [Figure 11] 1 is a schematic diagram of laser processing according to the above method. [Figure 12] 3 is a schematic diagram of a further embodiment of a contact element according to the present invention; [Figure 13] 5A-5C are schematic diagrams of laser processing of a further embodiment of a contact element according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0038] 1 shows a schematic representation of mating of a contact element 1 of a connector 3 with a mating contact element 39 of a mating connector 37. During mating, the contact element 1 moves relative to the mating contact element 39 along a relative insertion direction 43. Insertion of the connector into the mating connector 37 brings the contact area 8 of the contact element 1 into contact with the mating contact area 41 of the mating contact element 39. In the process, the resiliently deformable spring contacts 47 of the mating contact area 41 are forced apart to such an extent that the contact element 1 is held in a force fit between the spring contacts 47. Due to the contact pressure exerted by the spring contacts 47 on the contact surfaces 5 of the contact area 8, frictional forces act between the contact surfaces 5 and the spring contacts 47, which must be overcome during mating of the connector 3 with the mating connector 37. The force required to overcome the frictional forces, the so-called mating force, should be advantageously minimized by the configuration of the contact elements 1 of the connector 3 according to the invention.

[0039] 2, 3a, and 3b show various views of a contact element 1 of a connector 3 according to the present invention. FIG. 2 shows a side view of the contact element 1, which has a connection region 6 for attaching a required cable and a contact region 8 for establishing an electrical connection with a mating contact element 39. The contact region 8 comprises a main region 2 and an end region 4. The end region 4 is the portion of the contact element 1 that first makes contact with the mating contact element 39 upon mating, and is, for example, 1 mm in the illustrated embodiment. When the end region 4 makes contact with the spring contacts 47 of the mating contact region 41, a first mating force must be overcome to spread the spring contacts 47 apart. Only after the spring contacts 47 are first spread apart does the main region 2 make contact with the spring contacts 47. The spring contacts 47 continue to be spread apart by the main region 2 until the desired mating position is reached. As a result, it is clear that the end region 4 must overcome the greatest mating force when it comes into contact with the spring contacts 47.

[0040] FIG. 3a shows a top view of the contact element 1 with the end region 4. As can be seen from FIGS. 2 and 3a, the length of the contact element 1 extends in the x-direction along the longitudinal axis L. The contact region 8 preferably has four faces. The top face 50 visible in the plan view of FIG. 3 extends in the xy-plane. The bottom face 51 of the contact region 8 is arranged parallel to it (FIG. 2). The first face 52 and the second face 53 are arranged transversely to the top face 50 and the bottom face 51, respectively, in the xz-plane. Electrical contact between the contact element 1 and the mating contact element 39 is established via the contact surfaces 5 in the contact region 8. The contact surfaces 5 may be arranged on any number of faces 50, 51, 52, 53 of the contact region 8, advantageously arranged on at least one face of the main region 2 and at least one face of the edge region 4. Only the contact surfaces 5 of the edge region 4 partially have a surface texture 31, and cavities 7 filled with an auxiliary material 9 are arranged inside the contact surfaces 5 in the area of ​​the surface texture 31. The cavities 7 are arranged in the microstructures 11 inside the contact surfaces 5. In the illustrated embodiment, the contact surfaces 5 are arranged on an upper face 50 extending in the xy plane. The upper face 50 and the lower face 51 have a larger surface area than the first face 52 and the second face 53, for example.

[0041] By locating the microstructure and surface texture only in the end region 4 of the contact area 8, the mating force is advantageously minimized while maintaining the same electrical performance. During mating, any leaked auxiliary material is dispersed on the surface of the end region. This means that a smaller mating force is required to mate the two connectors 3, 37. At the same time, excess auxiliary material is prevented from reaching the contact surface 5 of the main region 2. Electrical contact between the contact element 1 and the mating contact element 39 occurs at this point. This means that electrical contact and a stable electrical connection are not affected by excess auxiliary material on the contact surface 5 of the main region 2.

[0042] 3b shows a further exemplary embodiment of the contact region 8 of the contact element 1. Advantageously, an intermediate portion 10 may be arranged between the end region 4 and the main region 2. In this advantageous embodiment, the intermediate portion 10 consists of an electrically conductive material. Preferably, the intermediate portion 10 is made of the same material as the main region 2. Advantageously, the end region 4 is made of a non-conductive material, such as plastic. However, it is also possible for the end region 4 to be made of an electrically conductive material. In this embodiment, the contact surfaces 5 are preferably arranged on at least one side of the end region 4, on at least one side of the intermediate portion 10, and on at least one side of the main region 2. The contact surfaces 5 in the end regions 4 and in the intermediate portion 10 partially have a surface texture 31, and cavities 7 filled with an auxiliary material 9 are arranged inside the contact surfaces 5 in the region of the surface texture 31. The cavities 7 are arranged in a microstructure 11 inside the contact surfaces 5. This embodiment is used in particular for high-current connectors, such as those used in electromobility, where a reduction in mating forces is particularly important. The other features of the contact element mentioned as advantageous are of course also applicable to this embodiment.

[0043] Advantageously, if the end region 4 is made from a non-conductive material with a low melting or softening temperature, such as a plastic, for example between 100 and 400°C, the conductive coating 25 may not be provided, since the base material 13 can be formed to form a cavity 7 with the auxiliary material 9. However, the non-conductive coating 25 may be applied to the end region 4, which is advantageous for forming a cavity 7 enclosing the auxiliary material 9.

[0044] 4 to 8 show various advantageous embodiments of the contact region 8 of the contact element 1. The orientation of the contact region 8 is defined in each case in the adjacent coordinate system. FIG. 4 shows a top view of the upper surface 50 of the contact region 8, and FIG. 4b shows a top view of the first face 52 of the contact region 8. According to advantageous embodiments of the contact region 8, the upper surface 50 and the lower surface 51 of the contact region 8 are, for example, textured and have a microstructure 11.

[0045] In addition, the surface of the end region 4 tapers along the longitudinal axis L in the insertion direction of the contact element 1. The lower surface 51 and the second surface 53 of the contact region 8 correspond in shape to the upper surface 50 and the first surface 52. In the illustrated FIGS. 4a and 4b, the contact region 8 has an upper surface 50 with a larger surface area than the first surface 52. The end regions of the illustrated upper surface 50 and the first surface 52 each have a different shape. Both shapes represent embodiments of the end region according to the present invention, on each of which a contact surface 5 may be arranged. In this case, a reduction in mating force is achieved both through the advantageous design of the edge contour 30 and the advantageous design of the upper surface 50 and the lower surface 51 of the end region 4 with texture and microstructure.

[0046] The tapering of the surface along the longitudinal axis L is shown in detail in FIG. 5 as an example for a first surface 52. The first surface 52 has upper and lower edge profiles 30, where the terms "upper" and "lower" are defined along the z-axis with respect to the longitudinal axis L. The two edge profiles 30 converge such that each edge profile 30 at least partially follows the path of a cubic function graph. The path of the cubic function graph depends on the path of the longitudinal axis L. Thus, for example, the upper edge profile 30 follows a cubic function graph along the longitudinal axis L. The same applies to the lower edge profile 30.

[0047] Furthermore, the cubic function graph paths of the upper and lower edge contours 30 of the first surface 52 shown in FIG.

number

[0048] However, it is expressly understood that in further advantageous embodiments, the surface of the end region 4 having an edge profile according to formula (1) can also be textured and have a microstructure 11. Consequently, any surface may have these advantageous features in combination or individually.

[0049] For example, in this embodiment, the upper surface 50 and the lower surface 51 have a width b1 of 1.2 mm, and the first surface 52 and the second surface 53 have a width b2 of 0.6 mm. However, this embodiment is not limited to this size, and any connector width may be realized depending on the application. Advantageously, the connector width b1 ranges from 0.3 mm to 12 mm, and the connector width b2 ranges from 0.3 mm to 2 mm.

[0050] A further advantageous embodiment of the contact region 8 is shown in FIG. 6. FIG. 6a shows a top view of the upper surface 50 of the contact region 8, and FIG. 6b shows a top view of the first surface 52 of the contact region 8. In this embodiment, all surfaces 50, 51, 52, 53 correspond to formula (1). In particular, the contact region 8 in this advantageous embodiment has contact surfaces 5 on all surfaces 50, 51, 52, 53 of the end region, which have a surface texture and inside which cavities filled with an auxiliary material are arranged. This embodiment is particularly suitable for square plugs, in which case contact surfaces are arranged on all four surfaces 50, 51, 52, 53. For example, the width b2 of the contact region 8 is 0.63 mm for both the upper surface 50 and the lower surface 51, as well as for the first surface 52 and the second surface 53. However, it is understood that other dimensions of the surfaces are also within the meaning of this embodiment.

[0051] Therefore, it is clear that the embodiments shown for the upper surface 50 and the first surface 52 also apply to the lower surface 51 and the second surface 53 .

[0052] FIG. 7 shows a further advantageous embodiment of the upper surface 50 and the first surface 52 of the contact region 8. FIGS. 7a and 7b show two advantageous embodiments of the upper surface 50 of the contact region 8. The respective end regions 4 are formed differently. FIG. 7c shows a further advantageous embodiment of the first surface 52 of the contact region 8. The first surface 52 has a larger surface area than the embodiment shown in FIG. 6b. For example, the surfaces 52, 53 have a width b3 of 0.8 mm.

[0053] Figure 8 shows a further advantageous embodiment of the first surface 52 of the contact area 8, in which the end area 4 is shown to be truncated. The cutting line S in Figure 8 indicates that the end area 4 may be truncated as long as the connector does not deviate from the scope of the invention, and still achieve the positively mentioned advantages of the invention.

[0054] These different embodiments are used with different connector types having different contact areas, and are intended to illustrate that the contact elements and methods described above can be used with a variety of different connector types and are therefore not limited to any particular type of connector.

[0055] A method is described below for encapsulating the auxiliary material 9 inside the contact surface 5 of the end region 4 of the contact area 8 of the contact element 1. It is clear that the method described below can also be used to encapsulate the auxiliary material in a contact element having an end region 4 and an intermediate portion 10.

[0056] FIG. 9 shows a method for encapsulating a supplemental material 9 inside a contact surface 5. The starting material for this method is a contact area 8 of a contact element 1 of a connector 3, which comprises a main area 2, an end area 4, and a contact surface 5 for mechanical and electrical contact with a mating contact element 39 of a mating connector 37. The main area 2 is electrically conductive and consists of a base material 13. The base material 13 may be, for example, copper or a copper alloy. In addition, as shown in FIG. 9a, for example, a coating 25 may be applied to the surface of the base material 13. The coating 25 may, for example, contain tin, nickel, silver, or an alloy of tin, nickel, silver, and / or other elements. The coating 25 can be applied to the base material 13, for example by hot-dip tinning or electroplating, thereby enabling further intermediate layers. The side of the coating 25 facing away from the base material forms the contact surface 5. The end region 4 can also be electrically conductive; the same applies to the main region 2. If the end region 4 is made of a non-conductive material, such as a plastic, with a low melting or softening temperature, for example between 100 and 400°C, it is advantageous not to provide the conductive coating 25, since the base material 13 can be formed to form a cavity 7 containing the auxiliary material 9. However, the non-conductive coating 25 can also be applied to the end region 4, which is advantageous for forming the cavity 7 containing the auxiliary material 9.

[0057] First, the auxiliary material 9 is applied to the contact surface 5. For example, the contact surface 5 may be completely covered with the auxiliary material 9, for example as shown in Figure 9a. The auxiliary material 9 may be oil, grease, paste or solid lubricant such as graphite, CNT, MoS2, AgS2 or mixtures thereof.

[0058] After the auxiliary material 9 has been applied to the contact surface 5, the microstructures 11 are then formed. In the illustrated exemplary process, the auxiliary material 9 is encapsulated in the microstructures 11 during their formation. For this purpose, the contact surface is treated with an interference pattern 27 by means of laser radiation 29, 29'. Advantageously, by using a laser, very large contact surfaces can be microstructured in a very short time.

[0059] In the illustrated embodiment, for example, the microstructure 11 consists of periodically alternating ridges 15 and recesses 17, with the recesses 17 forming grooves and the ridges forming walls between them, resulting in a regular periodic strip structure as the microstructure 11 with a period length p.

[0060] In laser interference texturing, two or more superimposed, preferably coherent or linearly polarized, laser beams 29, 29' generate a specifically adjustable interference pattern 27. A prerequisite for this is the spatial and temporal coherence of the laser beams 29, 29'. Spatial coherence can be impaired by interaction with the environment or with the optical elements of the device for generating the interference radiation. Temporal coherence depends on the spectral bandwidth λ of the laser radiation 29, 29'. The common coherence length of the spectral bandwidth ranges from 266 to 1064 nm.

[0061] By selecting the laser radiation and the number and alignment of the laser beams relative to one another, different interference patterns 27 can be generated, e.g., line patterns, dot patterns, honeycomb patterns, cross patterns, etc. The interference patterns 27 define the microstructure 11 and surface texture 31 of the contact surface 5 of the end region 4.

[0062] When the contact surface 5 of the edge region 4 is treated with an interference pattern 27 consisting of laser radiation 29 and 29', two or more superimposed coherent linearly polarized laser beams 29 and 29' generate a specifically adjustable interference pattern 27. The intensity of the laser radiation is distributed within the interference pattern 27. In the case of positive interference (+), this increases, resulting in particularly hot areas where the contact surface 5 of the edge region 4 melts. On the other hand, at minimum intensity due to negative interference (-), the contact surface 5 of the edge region 4 is significantly cooler, so that the contact surface 5 of the edge region 4 does not melt, in other words, the auxiliary material 9 located at this point remains present, while in the areas of positive interference it evaporates. Additionally, the large temperature gradient between the lowest temperature (in the area of ​​negative interference) and the highest temperature (in the area of ​​positive interference) causes convection of molten material on the contact surface 5 of the end region 4 and the formation of texture 31. Texture 31 is formed by the transport of material on the contact surface 5 of the end region 4 from the hottest area to the coldest area.

[0063] When the contact surface 5 of the edge region 4 of the conductive contact area 8, coated with a layer of auxiliary material 9, is irradiated with an interference pattern 27 consisting of laser radiation 29 and 29' (FIG. 9a), the following occurs: In the areas of positive interference (+), the auxiliary material 9 evaporates and volatilizes, while in the areas of negative interference (-), the auxiliary material 9 remains on the contact surface 5 of the edge region 4. Furthermore, the material of the contact surface 5 of the edge region 4 melts in the areas of positive interference and overflows, being guided to the areas of negative interference, where it forms bumps 15 and covers the remaining auxiliary material 9. This allows the contact surface 5 of the edge region 4 to be formed as shown in FIGS. 9b and 9c, which has a nodule-like structure 33, each of which has a cavity 7 filled with auxiliary material.

[0064] Thus, during interference texturing, as the microstructures 11 are formed, the auxiliary material 9 is encapsulated in the microstructures 11. At the same time, texturing 31 of the contact surface 5 of the end region 4 occurs. In the illustrated embodiment, the surface texture 31 is formed by a nodular structure 33 with regularly arranged nodules 35 and recesses 17 therebetween. In the illustrated embodiment, the surface texture 31, i.e., the nodular structure 33, matches the microstructure 11 of the cavities 7 filled with the auxiliary material 9. The surface texture 31 is raised above the cavities 7 of the microstructure 11. In the illustrated example, a cavity 7 filled with the auxiliary material 9 is located in each nodule 35.

[0065] In FIG. 10, a portion of a contact element 1 according to the invention having a conductive contact area 8 is shown in a schematic partial cross-section when plugged into a mating contact element 39 .

[0066] The contact area 8 is designed, for example, as a contact pin and is shown in a cross-sectional view. The contact area 8 is electrically conductive and consists of a base material 13, for example copper or a copper alloy. The contact area 8 has a contact surface 5. Inside the contact surface 5, cavities 7 filled with an auxiliary material 9 are arranged in a microstructure 11. The contact surface 5 in the illustrated embodiment has a surface texture 31 consisting of periodically alternating bumps 15 and depressions 17. A cavity 7 of the microstructure 11 filled with the auxiliary material 9 is arranged in each bump 15. The surface texture 31 and the microstructure 11 of the contact area 8 in FIG. 10 thus substantially corresponds to those in FIG. 9, except that the coating 25 is omitted and the auxiliary material 9 is applied directly to the base material 13.

[0067] 10 also shows a portion of a mating contact element 39 of a mating connector 37. The mating connector 37 is intended for a plug-in connection with the connector 3. The mating contact element 39 has a mating contact area 41 which comes into contact with the contact area 8 of the contact element 1 when the connector 3 is mated with the mating connector 37. The mating contact area 41 is designed as an elastically deformable spring contact.

[0068] When the connector 3 and the mating connector 37 are plugged together as shown in Figure 10, the further contact surfaces of the mating contact area 41 come into contact with the contact surfaces 5 of the contact area 8 to establish a conductive connection. During mating of the connector 3 with the mating connector 37, the contact elements 1 move relative to the mating contact elements 39 along a relative insertion direction 43.

[0069] Due to the contact pressure exerted by the mating contact region 41 of the mating contact element 39 on the contact region 8 of the contact element 1, frictional forces act between the contact surface 5 and the other contact surface of the mating contact region 41, which must be overcome during mating of the connector 3 with the mating connector 37. To reduce these forces, the contact surface 5 is provided with a surface texture 31. In addition, the surface texture 31 and the microstructure 11 in the end region 4 of the contact region 8 are partially destroyed during mating. The frictional forces create access to a closed cavity 7 pre-arranged inside the contact surface 5. The cavity 7 opens towards the contact surface 5. The auxiliary material 9 can leak out of the cavity 7 and form a thin film 45 of the auxiliary material 9 on the contact surface 5, which has the desired positive effect, for example, reducing friction and protecting against corrosion.

[0070] FIG. 11 shows a schematic diagram of the position and orientation of the laser relative to the contact elements 1 during laser interference texturing. As an example, a large number of contact elements 1 are arranged close to one another. FIG. 11 shows an exemplary top view of a plurality of contact elements 1. Such an arrangement of contact elements 1, one side of which is fixed to a carrier rail, is used to enable processing a large number of contact elements as quickly and efficiently as possible in an automated laser-based process. The distance between two adjacent contact elements 1 may be, for example, 1.2 mm.

[0071] As a result, it is clear that with such an arrangement, laser treatment of the main region 2 of the contact area 8 is only possible to a limited extent. Only one side facing the laser can be treated with laser radiation. Therefore, it is almost impossible to treat the side of the main region 2 facing the adjacent contact element 1.

[0072] Advantageously, in the method described above, only the end regions 4 of the contact areas 8 are treated with laser radiation. This method can thus be used to simply and cost-effectively treat closely arranged contact elements 1 on a carrier rail with laser radiation.

[0073] As shown in Figure 11, the laser radiation strikes the contact surface 5 of the end region 4 in a direction transverse to the contact surface 5. This ensures a uniform surface treatment in the desired area. However, the laser radiation does not strike perpendicular to the longitudinal axis L of the contact element 3. This axis extends along the entire length of the contact element. In particular, the angle β between the longitudinal axis L of the contact element 1 to be treated and the laser radiation lies in the range 0°<β<90°.

[0074] 12 shows another exemplary embodiment of the contact element 1. In this embodiment, the contact region 8 has faces 52, 53 that are larger in area than the upper and lower faces 50, 51. The left and right faces 52, 53 also extend in the xz-plane in this embodiment, while the upper and lower faces 50, 51 extend in the xy-plane. By way of example, the surfaces to be textured in the end region 4 of the contact region 8 are located on faces 52, 53.

[0075] 13, the method described above allows for the surface treatment by means of laser radiation 29, 29' of contact elements 1 mounted on a carrier rail 49 and having surfaces 52, 53 to be treated. As mentioned above, the distance between two contact elements 1 arranged next to each other on the carrier rail 49 is too small to allow the entire surface to be textured. [Explanation of symbols]

[0076] 1 Contact Elements 2 Main area 3 Connectors 4 End area 5 Contact Surface 6 Connection Area 7 Cavity 8 Contact Area 9 Auxiliary materials 10 Middle part 11 Microstructure 13 Base Material 15 Ridge 17 Recess 19 Uniform Pattern 25 Coating 27 Interference Pattern 29, 29' Laser radiation 30 Edge outline 31 Surface Texture 33 Lumbar structure 35 Aneurysm 37 Mating connector 39 Counterpart Contact Element 41 Counterpart Contact Area 43 Insertion direction 45 Thin films formed from auxiliary materials 47 Spring Contact 49 Carrier Rail 50 Top 51 Bottom surface 52 First Side 53 Second Side L Longitudinal axis S cutting line p period length λ spectral bandwidth laser radiation a Spacing of connectors on carrier rail + Positive Interference - Negative Interference α angle β angle

Claims

1. A conductive contact element (1) for an electrical connector (3), comprising: The conductive contact element (1) comprises a connection area (6) and a contact area (8), said contact area (8) comprising a main area (2), end areas (4) and contact surfaces (5) for electrical contact with mating contact elements (39) of a mating connector (37); the contact surfaces (5) are arranged on at least one face (50, 51, 52, 53) of the main region (2) and on at least one face (50, 51, 52, 53) of the end region (4), Only inside the contact surface (5) of the end region (4), cavities (7) filled with an auxiliary material (9) are arranged in the microstructure (11), the contact surface (5) has a surface texture (31) partially in the area of ​​the microstructure (11); A conductive contact element (1).

2. The surface texture (31) comprises ridges (15) and recesses (17). The conductive contact element (1) according to claim 1.

3. the surface texture (31) comprises a predetermined pattern of geometric elements; The conductive contact element (1) according to claim 1.

4. The microstructure (11) forms an at least partially periodic structure. The conductive contact element (1) according to claim 1.

5. the geometric elements of the surface texture (31) are raised above each cavity (7) of the microstructure (11); The conductive contact element (1) according to claim 1.

6. at least two faces (50, 51, 52, 53) of the end region (4) of the contact region (8) are tapered along the longitudinal axis (L) in the insertion direction (43) of the conductive contact element (1); The conductive contact element (1) according to claim 1.

7. the at least two tapered surfaces (50, 51, 52, 53) of the end region (4) each have two converging edge profiles (30) that converge such that each edge profile (30) at least partially follows the path of a cubic function graph; The path of the cubic function graph depends on the path of the longitudinal axis (L), The conductive contact element (1) according to claim 6.

8. The cubic function graph is [Equation 1] According to the formula, x ０ = the total length of said main region (2), d = the nominal thickness of said main region (2), and x follows the path of said longitudinal axis L; The conductive contact element (1) according to claim 7.

9. The auxiliary material (9) is selected from the group consisting of antioxidants, corrosion inhibitors, lubricants and acids. The conductive contact element (1) according to claim 1.

10. An electrical connector (3) comprising a conductive electrical contact element (1) according to any one of claims 1 to 9.

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